\begin{table}%T1
\caption{\label{tab:droverr}Expected sign of the three individual shifts, and corresponding prediction about planetary migration.}
%\centering
\par
\begin{tabular}{lcccc}
\hline\hline
 Shift             & ILRs    &  OLRs     & Contribution & Inward migration\\ \hline 
$\delta R_1$                 &  $>$0     & $>$0                 & outwards & slowed down \\ 
$\delta R_2 $      & $>$0    &  $<$0     & inwards & accelerated\\ 
$\delta R_3$       & $<$0    &  $<$0     & inwards & accelerated \\ 
total & $>$0    &  $<$0     & {\bf inwards} & {\bf accelerated} \\  \hline
\end{tabular}
\end{table}